Hello k.akhtar

I hope you are doing good . I would  glad to tell you that their are many central universities in india for btech to do in . Some of universities are the given below which do have very high nirf ranking and low fees structure:-

JNU Jawaharlal Nehru university: Delhi/NCR

Tezpur university: Tezpur

Universityof Delhi : Delhi/NCR

BHU Banaras Hindu University: Varanasi

Indira Gandhi National Open University IGNOU : Delhi/NCR

Jamia Millia Islamia University: Delhi/NCR

Allahabad university: AllahabadAssam university: Silchar.

Universites like JAMIA,BHU give admission on the basis of rank scored in jee mains as they are tier-1 colleges you should very good jee  percentile to take admission in these colleges

Hope you found this answer helpful. Good luck for your future